ChatGPT 3.5 and GPT 4?

General
1

How do I see the drop-down menu to switch between ChatGPT 3.5 and GPT 4?

2

You need to purchase ChatGPT Plus from OpenAI

3

Thank you Chrisophc,
I have now done that. I purchased AIPRM Pro unnessasarily.
I only wanted to use GPT4